Light-hole exciton in a nanowire quantum dot

Abstract

Quantum dots inserted inside semiconductor nanowires are extremely promising candidates as building blocks for solid-state based quantum computation and communication. They provide very high crystalline and optical properties and offer a convenient geometry for electrical contacting. Having a complete determination and full control of their emission properties is one of the key goals of nanoscience researchers. Here we use strain as a tool to create in a single magnetic nanowire quantum dot a light-hole exciton, an optically active quasiparticle formed from a single electron bound to a single light hole. In this frame, we provide a general description of the mixing within the hole quadruplet induced by strain or confinement. A multi-instrumental combination of cathodoluminescence, polarisation-resolved Fourier imaging and magneto-optical spectroscopy, allow us to fully characterize the hole ground state, including its valence band mixing with heavy hole states. arXiv:1612.01563v1 [cond-mat.mes-hall]

N -induced Quantum Dots in GaAs/Ga(N,Jansson1, Ishikawa2, Chen3 et al. 2018Phys. Rev. Applied62130View full textAdd to dashboardCite

“…On the other hand, the ordering of the VB states may be significantly altered and even reversed when the QDs are embedded in the core/shell NW, where the strain that is created due to the lattice mismatch between the core and shell materials is uniaxial along the NW axis [19].…”

Light-hole states in a strained quantum dot: numerical calculation and phenomenological models

“…Experimentally, the LH ground state was obtained in a GaAs QD with a tensile stress applied in-plane by a piezoelectric device [21,22]. The ground state is also a light-hole in an elongated QD with a compressive mismatch, as shown theoretically [23][24][25] and demonstrated experimentally in QDs embedded in a * joel.cibert@neel.cnrs.fr nanowire [16]. In the first case, the applied strain must overcompensate the built-in strain and the confinement; in the second case, they all play into the same direction.…”

“…Recent studies have demonstrated the interest of a more accurate positioning in a waveguiding nanowire [7,8] and even the possibility to insert the structure into a complete optical circuit [9][10][11]. Such nanowires containing a QD have been grown mostly from InP [7,8,12,13], but nanowire-QDs have been also demonstrated with other materials such as CdSe [14], or CdTe [15,16]. Particularly sharp lines are obtained in the case of III-Vs.…”

Regulated dynamics with two-monolayer steps in vapor-solid-solid growth of nanowires

“…The strong electronhole interaction gives rise to a large excitonbiexciton splitting, so that single photon emission was demonstrated up to room temperature in CdSe quantum dots embedded in a ZnSe nanowire. 40 This dot-nanowire configuration in CdTe-ZnTe allows one to adjust the built-in strain in order to manipulate the magnetic properties introduced through Mn impurities 41,42 or to control the light-hole heavy-hole character of the ground state 43 for an increased flexibility of the optical and spin properties. ZnTe nanowires can be grown by MBE using a gold seed, on GaAs or Si substrates, [44][45][46] where the growth mode is assumed to be VLS due to the formation of a eutectic of gold with gallium or silicon, or on ZnTe buffer layer, 47 where the growth mode is assumed to be VSS.…”